Tremolos for stringed musical instruments are known. Such devices are used to decrease the tension of the strings of the instrument to lower its tone, or to increase tension of the strings raising the tone. Such devices may be adapted for use in a variety of stringed instruments, typically multiple-stringed instruments such as guitars, cellos, mandolins, etc.
A tremolo device is typically provided with a lever or tremolo arm used to effect a movement in the tremolo thereby increasing or decreasing tension on the guitar strings. In an electric guitar, tremolo arm is often called a "whammy bar". The tremolo of an electric guitar is typically located adjacent the transducers located on the body of the guitar. Typically, such tremolos include means for fixing an end of each of a number guitar strings and means for bridging the guitar strings adjacent the fixed ends of the strings. Often the means for fixing the string end and bridging the string is provided in a saddle separable from a string support plate of the tremolo. The string support plate is pivotally mounted relative to the body of the guitar and its pivotal movement is actuated by the tremolo arm. Pivotal engagement of the string support plate with the guitar body may be provided by a number of known means, including a hinge apparatus such as the trunnions of Canadian patent no. 855,961, or the knife-edge articulating means described in U.S. Pat. No. 4,171,661. Often, a tremolo is pivotally mounted on the body of an electric guitar over a cavity in the body of sufficient size to permit the string support plate of the tremolo to pivot into or towards the cavity when increased tension on the guitar strings is effected. Typically, a tremolo lever such as a flange depends from a side of the string support plate facing the cavity and extends into the cavity. As is shown in U.S. Pat. Nos. 2,741,146 and 4,171,661, the tremolo lever may be connected to the guitar body by a resilient element such as a spring within the cavity. Such resilient means are used to counteract tension of the guitar strings so as to maintain the tremolo at a neutral point at which the guitar is tuned. Such an arrangement is often called a floating tremolo, although fixed stops may be incorporated to limit the lever or the bridge support plate of the tremolo.
As a tremolo's primary function is to affect the string tension, it is not essential that the tremolo include means for fixing a string end or for bridging the string since such means may be provided elsewhere on the guitar body adjacent the tremolo device. For example, the tremolo may include means to fix a guitar string end whereas the bridge is provided on the guitar body adjacent the tremolo. A variety of string fixation means are known which rely upon either restraint of a bead mounted on the end of the string, clamping the string, or both methods.
Until now, advances in design of tremolos have related to the bridging and string fixation means, or in the means for locating and stabilizing the pivotal movement of a tremolo in order to maintain the instrument in tune during extended use of the tremolo or after string breakage. Prior to this invention, tremolos simultaneously affected all of the strings engaged by the tremolo without provision for a differential effect with respect to different strings.